1. Field of the invention
The present invention relates to a profile assembly for wedge-sealing an edge of a sheet of flexible material. In its preferred form, the invention is part of a window shade sealing system for sealing the lateral edges of a window shade covering a window having lateral frame members, the system then having two profile assemblies, each disposed along one of the two lateral window frame members, for sealing the border edges of the shade.
2. Description of the prior art
Many attempts have been made in recent years, due to the increasing costs of heating buildings of all types, to reduce heat dissipation by leakage of outside air through windows. One solution has been to use permanent thermal window glass or to provide windows with a double pane but these solutions are expensive. Less expensive has been the use of sheets of transparent material fixed over the frame of windows by adhesive strips but this solution is not found efficient, convenient nor aesthetic. More efficient structures have also been suggested which reside in the use of a flexible sheet of transparent material, such as polyethylene, wound on a roller mounted in a housing and drawn through a pay-out slot; the edges of the shade being slid along guide channels and sealed therein in various ways. Structures of this type are known to Applicant from the following U.S. patents:
2,509,398 of 1950 PA1 3,225,407 of 1965 PA1 3,783,931 of 1974 PA1 3,803,671 of 1974 PA1 4,467,504 of 1984
Of relevance with respect to the present invention, are U.S. Pat. No. 4,220,189 and U.S. Pat. No. 4,480,676. In the former, a spring clip presses the edge of the sheet against a flat surface. As the shade is drawn down through the guide channel, difficulty arises if the pressure of the clip is too strong, and air tends to seep through the channel if the clip is too weak, which may happen if the clip loosens with use. In the latter U.S. Pat. No. 4,480,676, spaced sealing members press lightly on opposite sides of the edges of the shade to give it a curvilinear configuration purporting to seal the edge of the shade. However, the sealing members do not really press on the shade but rather simply guide it in the curvilinear configuration rendering sealing rather haphazard. Perhaps more pertinent to the present invention are the attaching devices of the other two U.S. Pat. Nos. 3,803,671 and 4,467,504. In both cases, a channel-shaped housing, having a vertical opening, receives the edge of the flexible shade which is forcibly pressed therein by a plug. The sealing is efficient but the structure, both of the housing and of the plug, is complex and thus expensive as well as difficult to handle both in securing the shade edge in the housing and in removing the plug from it.